/*
** $Id: lobject.c,v 2.58 2013/02/20 14:08:56 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define lobject_c
#define LUA_CORE

#include "lua.h"

#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"



LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};


/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee != 0 and (xxx) otherwise.
*/
int luaO_int2fb (unsigned int x) {
	int e = 0;  /* exponent */
	if (x < 8) return x;
	while (x >= 0x10) {
		x = (x+1) >> 1;
		e++;
	}
	return ((e+1) << 3) | (cast_int(x) - 8);
}


/* converts back */
int luaO_fb2int (int x) {
	int e = (x >> 3) & 0x1f;
	if (e == 0) return x;
	else return ((x & 7) + 8) << (e - 1);
}


int luaO_ceillog2 (unsigned int x) {
	static const lu_byte log_2[256] = {
		0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
	};
	int l = 0;
	x--;
	while (x >= 256) { l += 8; x >>= 8; }
	return l + log_2[x];
}


lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
	switch (op) {
	case LUA_OPADD: return luai_numadd(NULL, v1, v2);
	case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
	case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
	case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
	case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
	case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
	case LUA_OPUNM: return luai_numunm(NULL, v1);
	default: lua_assert(0); return 0;
	}
}


int luaO_hexavalue (int c) {
	if (lisdigit(c)) return c - '0';
	else return ltolower(c) - 'a' + 10;
}


#if !defined(lua_strx2number)

#include <math.h>


static int isneg (const char **s) {
	if (**s == '-') { (*s)++; return 1; }
	else if (**s == '+') (*s)++;
	return 0;
}


static lua_Number readhexa (const char **s, lua_Number r, int *count) {
	for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
		r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
		(*count)++;
	}
	return r;
}


/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
	lua_Number r = 0.0;
	int e = 0, i = 0;
	int neg = 0;  /* 1 if number is negative */
	*endptr = cast(char *, s);  /* nothing is valid yet */
	while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
	neg = isneg(&s);  /* check signal */
	if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
		return 0.0;  /* invalid format (no '0x') */
	s += 2;  /* skip '0x' */
	r = readhexa(&s, r, &i);  /* read integer part */
	if (*s == '.') {
		s++;  /* skip dot */
		r = readhexa(&s, r, &e);  /* read fractional part */
	}
	if (i == 0 && e == 0)
		return 0.0;  /* invalid format (no digit) */
	e *= -4;  /* each fractional digit divides value by 2^-4 */
	*endptr = cast(char *, s);  /* valid up to here */
	if (*s == 'p' || *s == 'P') {  /* exponent part? */
		int exp1 = 0;
		int neg1;
		s++;  /* skip 'p' */
		neg1 = isneg(&s);  /* signal */
		if (!lisdigit(cast_uchar(*s)))
			goto ret;  /* must have at least one digit */
		while (lisdigit(cast_uchar(*s)))  /* read exponent */
			exp1 = exp1 * 10 + *(s++) - '0';
		if (neg1) exp1 = -exp1;
		e += exp1;
	}
	*endptr = cast(char *, s);  /* valid up to here */
ret:
	if (neg) r = -r;
	return l_mathop(ldexp)(r, e);
}

#endif


int luaO_str2d (const char *s, size_t len, lua_Number *result) {
	char *endptr;
	if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
		return 0;
	else if (strpbrk(s, "xX"))  /* hexa? */
		*result = lua_strx2number(s, &endptr);
	else
		*result = lua_str2number(s, &endptr);
	if (endptr == s) return 0;  /* nothing recognized */
	while (lisspace(cast_uchar(*endptr))) endptr++;
	return (endptr == s + len);  /* OK if no trailing characters */
}



static void pushstr (lua_State *L, const char *str, size_t l) {
	setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
}


/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
	int n = 0;
	for (;;) {
		const char *e = strchr(fmt, '%');
		if (e == NULL) break;
		luaD_checkstack(L, 2);  /* fmt + item */
		pushstr(L, fmt, e - fmt);
		switch (*(e+1)) {
		case 's': {
			const char *s = va_arg(argp, char *);
			if (s == NULL) s = "(null)";
			pushstr(L, s, strlen(s));
			break;
				  }
		case 'c': {
			char buff;
			buff = cast(char, va_arg(argp, int));
			pushstr(L, &buff, 1);
			break;
				  }
		case 'd': {
			setnvalue(L->top++, cast_num(va_arg(argp, int)));
			break;
				  }
		case 'f': {
			setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
			break;
				  }
		case 'p': {
			char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
			int l = sprintf(buff, "%p", va_arg(argp, void *));
			pushstr(L, buff, l);
			break;
				  }
		case '%': {
			pushstr(L, "%", 1);
			break;
				  }
		default: {
			luaG_runerror(L,
				"invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
				*(e + 1));
				 }
		}
		n += 2;
		fmt = e+2;
	}
	luaD_checkstack(L, 1);
	pushstr(L, fmt, strlen(fmt));
	if (n > 0) luaV_concat(L, n + 1);
	return svalue(L->top - 1);
}


const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
	const char *msg;
	va_list argp;
	va_start(argp, fmt);
	msg = luaO_pushvfstring(L, fmt, argp);
	va_end(argp);
	return msg;
}


/* number of chars of a literal string without the ending \0 */
#define LL(x)	(sizeof(x)/sizeof(char) - 1)

#define RETS	"..."
#define PRE	"[string \""
#define POS	"\"]"

#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )

void luaO_chunkid (char *out, const char *source, size_t bufflen) {
	size_t l = strlen(source);
	if (*source == '=') {  /* 'literal' source */
		if (l <= bufflen)  /* small enough? */
			memcpy(out, source + 1, l * sizeof(char));
		else {  /* truncate it */
			addstr(out, source + 1, bufflen - 1);
			*out = '\0';
		}
	}
	else if (*source == '@') {  /* file name */
		if (l <= bufflen)  /* small enough? */
			memcpy(out, source + 1, l * sizeof(char));
		else {  /* add '...' before rest of name */
			addstr(out, RETS, LL(RETS));
			bufflen -= LL(RETS);
			memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
		}
	}
	else {  /* string; format as [string "source"] */
		const char *nl = strchr(source, '\n');  /* find first new line (if any) */
		addstr(out, PRE, LL(PRE));  /* add prefix */
		bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
		if (l < bufflen && nl == NULL) {  /* small one-line source? */
			addstr(out, source, l);  /* keep it */
		}
		else {
			if (nl != NULL) l = nl - source;  /* stop at first newline */
			if (l > bufflen) l = bufflen;
			addstr(out, source, l);
			addstr(out, RETS, LL(RETS));
		}
		memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
	}
}

